But more recent chemists think that to make Cachoo, Adams was actually pilfering one of the dyes that he was supposed to be selling. Dianisidine is a chemical that, with coal tar, makes a beautiful blue dye. It's also carcinogenic and, according to the CDC should be flushed from every part of the body it makes contact with. A sneeze response would certainly help with that. Dianisidine was first discovered in 1894, when people noticed that it, in combination with copper salts, made a pretty color on fabrics that set in faster than indigo. People would have been using it a great deal, especially in the manufacturing centers, testing out new products.

Unfortunately, over a few years they found out that it ran when exposed to acid, or even heavy perspiration, bleeding blue on anyone who wore clothing dyed with it. Its color might have worked for soap products, but it was useless in clothing manufacturing. The repeated testing, would have given Adams ample opportunity to see people sneezing. The eventual abandonment of it as a potential clothing dye may have given him the ability to pick it up at a good price for his initial stock of Cachoo. But is that what he did?

Obviously, testing isn't an option. Few people are willing to get multiple facefulls of toxic chemicals in order to test which one makes them sneeze the most. So, although people are pretty sure that they've figured out the secret of Cachoo, this may be one of the eternal mysteries of the universe. Now the squirting lapel flower - that one we understand.